Many individuals, particularly the elderly, suffer from deposits which clog their arteries, more commonly referred to as atherosclerosis. Quite frequently, these deposits block or restrict the flow of blood in the coronary arteries. This condition may be debilitating or life-threatening to the individual, and corrective measures must be taken. Although some individuals may be treated with medication, in many cases surgery is required. Some arterial deposits may be removed or the arteries dilated with various surgical techniques, but these procedures do not work for every patient for very long. The condition may recur, requiring further action.
One procedure which has proven effective in combating atherosclerosis is to bypass the blocked artery with another blood carrying conduit. Typically material for an arterial bypass is one of the individual's own veins. More particularly, for coronary artery bypass, the saphenous vein is used. There are two ways in which a surgeon may use the individual's own vein. The vein may be harvested from the patient's leg, removed from the patient's body, and turned end for end before resetting the vein back into the body to be used to bypass the blocked artery. Turning the vein end for end ensures that the valves are oriented in the proper direction to allow the flow of blood. The valves in the vein may eventually adhere to the surface of the lumen wall. A second procedure is to employ a valvulotome to lyse or rupture and render incompetent the valves in the bypass vein. Often the use of the valvulotome causes areas of ulcerations in the vein which eventually become atherosclerotic.
When the clogged artery is in the distal arm or leg, an "in situ" bypass is often employed. In this procedure, since the vein is essentially left in place, the valves in the vein must be lysed or ruptured with a valvulotome before being attached to the artery in place of the blocked segment of artery.
Another problem associated with arterial reconstruction using veins is that after the procedure the veins become aneurysmal over time which increases the likelihood that the vein may rupture or become atherosclerotic. The art is in search of methods for improving the structural integrity of veins that are used in surgical procedures.